Immunodeficiency disorders

Immunodeficiency disorders occur when the body's immune response is reduced or absent.

Causes

The immune system is made up of lymphoid tissue in the body, which includes:

Bone marrow

Lymph nodes

Parts of the spleen and gastrointestinal tract

Thymus

Tonsils

Proteins and cells in the blood are also part of the immune system.

The immune system helps protect the body from harmful substances called antigens. Examples of antigens include bacteria, viruses, toxins, cancer cells, and foreign blood or tissues from another person or species.

When the immune system detects an antigen, it responds by producing proteins called antibodies that destroy the harmful substances. The immune system response also involves a process called phagocytosis. During this process, certain white blood cells swallow and destroy bacteria and other foreign substances. Proteins called complement help with this process.

Immunodeficiency disorders may affect any part of the immune system. Most often, these conditions occur when special white blood cells called T or B lymphocytes (or both) do not function normally or your body does not produce enough antibodies.

Inherited immunodeficiency disorders that affect B cells include:

Hypogammaglobulinemia, which usually leads to respiratory and gastrointestinal infections

Inherited immunodeficiency disorders that affect T cells may cause repeated Candida (yeast) infections. Inherited combined immunodeficiency affects both T cells and B cells. It may be deadly within the first year of life if it isn't treated early.

People are said to be immunosuppressed when they have an immunodeficiency disorder due to medicines that weaken the immune system (such as corticosteroids). Immunosuppression is also a common side effect of chemotherapy given to treat cancer.

Acquired immunodeficiency may be a complication of diseases such as HIV/AIDS and malnutrition (especially if the person does not eat enough protein). Many cancers may also cause immunodeficiency.

People who have had their spleen removed have an acquired immunodeficiency, and are at higher risk for infection by certain bacteria that the spleen would normally help fight. People with diabetes are also at higher risk for certain infections.

As you get older, the immune system becomes less effective. Immune system tissues (especially lymphoid tissue such as the thymus) shrink, and the number and activity of white blood cells drop.

The following conditions and diseases can lead to an immunodeficiency disorder:

Treatment

The goal of treatment is to prevent infections and treat any disease and infections that do develop.

If you have a weakened immune system, you should avoid contact with persons who have infections or contagious disorders. You may have to avoid people who have been vaccinated with live virus vaccines within the past 2 weeks.

If you develop an infection, your doctor will treat you aggressively. This may involve long-term use of antibiotic or antifungal drugs to prevent infections from coming back.

Interferon is used to treat viral infections and some types of cancer. It is a medicine that makes the immune system work better.

Persons with HIV/AIDS may take combinations of drugs to reduce the amount of HIV in their immune systems and improve their immunity.

People who are going to have a planned spleen removal should be vaccinated 2 weeks before the surgery against bacteria such as Streptococcus pneumonia and Haemophilus influenzae.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial policy, editorial process and privacy policy. A.D.A.M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 1997-2018, A.D.A.M., Inc. Duplication for commercial use must be authorized in writing by ADAM Health Solutions.